Torsemide
**Torsemide** is a highly potent **loop diuretic** primarily utilized in veterinary medicine as a "rescue" or adjunctive therapy for **congestive heart failure (CHF)** in dogs and cats. * **Potency**: Approximately **10 times more potent** than furosemide. * **Duration**: Offers a longer duration of action (~12 hours), allowing for less frequent dosing. * **Potassium-sparing**: In dogs, it exhibits less potassium excretion compared to furosemide, though monitoring is still essential. > **Clinical Pearl**: Torsemide is increasingly favored when patients develop **diuretic resistance** to furosemide, helping to manage severe pulmonary edema and ascites.
กลไกการออกฤทธิ์: Torsemide acts on the **thick ascending limb of the loop of Henle** in the kidneys. * It reversibly binds to and inhibits the **Na⁺/K⁺/2Cl⁻ (NKCC2) cotransporter** at the chloride-binding site → prevents the reabsorption of sodium and chloride. * This disruption abolishes the hypertonic medullary interstitium → prevents the concentration of urine → results in profound **diuresis** (excretion of water). * It also increases the renal excretion of potassium, calcium, magnesium, hydrogen, ammonium, and bicarbonate. In dogs, its potassium-wasting effect is notably less severe than that of furosemide.
ขนาดยาตามชนิดสัตว์
- Adjunctive treatment of refractory congestive heart failure · 0.2-0.3 mg/kg · PO · q12-24h · When other diuretics have become ineffective
- Congestive heart failure · 0.2 mg/kg · PO · once a day to three times a day
- Adjunctive treatment of refractory congestive heart failure · 0.2-0.3 mg/kg · PO · q12-24h · When other diuretics have become ineffective
- Congestive heart failure · 0.2 mg/kg · PO · once a day to three times a day
ขนาดยาเป็นข้อมูลอ้างอิงทางคลินิกสำหรับสัตวแพทย์ผู้มีใบอนุญาต โปรดตรวจสอบกับฉลากล่าสุดและผู้ป่วยแต่ละรายเสมอ
วิธีการให้ยา
ข้อห้ามใช้
- Known hypersensitivity to torsemide or other sulfonylureas
- Anuric patients
อาการไม่พึงประสงค์
- Fluid and electrolyte abnormalities (hyponatremia, hypocalcemia, hypokalemia, hypomagnesemia)
- Prerenal azotemia (secondary to dehydration)
- Gastrointestinal disturbances
- Hematologic effects (anemia, leukopenia)
- Weakness
- Restlessness
- Ototoxicity (rare, associated with rapid IV administration)
อันตรกิริยาระหว่างยา
- ACE Inhibitors (e.g., enalapril, benazepril) · Increased risks for hypotension, particularly in patients who are volume or sodium depleted secondary to diuretics
- Aminoglycosides (gentamicin, amikacin, etc.) · May increase the ototoxic or nephrotoxic risks of aminoglycosides
- Amphotericin B · May increase the risk for nephrotoxicity development
- Digoxin · Can increase the area under the curve of torsemide by 50%; torsemide-induced hypokalemia may increase the potential for digoxin toxicity
- Lithium · Torsemide may reduce lithium clearance
- NSAIDs · Some NSAIDs may reduce the natriuretic effects of torsemide
- Probenecid · Can reduce the diuretic efficacy of torsemide
- Salicylates · Torsemide can reduce the excretion of salicylates
การติดตาม
- Serum electrolytes (especially potassium, sodium, calcium, magnesium)
- BUN and creatinine
- Blood glucose (if diabetic)
- Hydration status
- Blood pressure (if indicated)
- Clinical signs of edema and patient weight
การได้รับยาเกินขนาด
In dogs, the oral LD50 is >2 grams/kg. **Fluid and electrolyte imbalance** is the most likely risk associated with an overdose. * Consider gut emptying protocols for very large or quantity unknown ingestions. * Acute overdoses should generally be managed by observation with fluid, electrolyte, and acid-base monitoring. * Supportive treatment should be initiated if required.
ข้อมูลอ้างอิงยาของ VetSheet มีไว้สำหรับสัตวแพทย์ผู้มีใบอนุญาตเพื่อช่วยในการตัดสินใจทางคลินิก ไม่ใช่สิ่งทดแทนการวินิจฉัยของผู้เชี่ยวชาญหรือฉลากล่าสุดของผู้ผลิต